平面滑动型岩质边坡地震动力响应

Seismic Dynamic Responses of Plane Sliding Rock Slope

为探讨地震荷载作用下顺层岩质边坡的失稳机理,采用疲劳强度理论分析地震载荷作用下边坡岩体力学性质的变化.将地震波简化为弹性波,对结构面产生等效静态应力,得出了顺层边坡沿结构面失稳的破坏判据,并以汶川地震中唐家山高速滑坡为例,验证了破坏判据的合理性.研究表明,顺层边坡沿结构面失稳主要取决于结构面倾角、内摩擦角、结构面两侧岩体的波阻抗以及地震波入射角,横波是造成边坡失稳的主要因素.对于唐家山高速滑坡,纵波最危险的入射角为0°和10°,横波最危险的入射角为10°和20°.

In order to investigate the stability-loss mechanism of a cataclinal rock slope under earthquake loading,the fatigue strength theory was used to investigate the changes of its mechanical properties under the action of the loading.Seismic waves were simplified as elastic waves to generate equivalent static stresses on a structural plane,and a stability-loss criterion about cataclinal rock slope sliding along the structural plane was obtained.Through taking Tangjiashan landsliding in the Wenchuan earthquake as an example,the rationality of the stability-loss criterion was verified.The research result indicates that sliding of a cataclinal rock slope along a structural plane depends mainly on the dip angle and internal friction angle of the structural plane,the wave impedance of rock masses on the both sides of the structural plane and the incident angle of seismic waves,and the transverse wave is the main factor causing the stability-loss of cataclinal rock slopes.To the Tangjiashan landsliding,the most dangerous incident angle is 0° and 10° to the longitudinal wave and 10° and 20° to the transverse wave.